Injection device with flexible dose selection

Abstract

An injection device incorporating a dose setting mechanism is presented where the dose setting mechanism contains a dose selector having one or more dose stops corresponding to a finite set of predetermined fixed doses, where the set of finite predetermined fixed doses includes a lowest fixed dose and one or more higher fixed doses, and where at least one of the one or more higher fixed doses is equal to the lowest fixed dose plus a fractional amount of the lowest fixed dose. The dose setting mechanism can further include a floating spline that is rotationally engaged with a snap element such that the snap element can rotate relative to the floating spline during both dose setting and dose delivery.

Description

TECHNICAL AREA[0001]The present disclosure relates to an injection device and particularly to the dose setting mechanism of the injection device, where a user can select one or more predetermined fixed dose settings as a direct result of the design and manufacture of a single component of the dose setting mechanism. Changing the design of this single component of the dose setting mechanism allows for the efficient manufacture of injection devices that can be custom made for a specific dosing regimen and / or used in dose-ranging evaluations.BACKGROUND[0002]There are a number of medicament delivery devices on the market that are capable of automatically, semi-automatically or manually delivering doses of medicament. Of the known type of delivery devices the “pen-type” injector is gaining in popularity and is available in both reusable and disposable designs. Such devices are constructed with dose setting mechanisms that include a variety of inter-acting components for obtaining desired...

AI Technical Summary

Benefits of technology

[0010]The snap element rotates relative to the floating spline and the dose selector during both dose setting and dose delivery. This is due to the floating spline being rotationally fixed to the dose selector through corresponding splines on an inner surface of the dose selector. Since the dose selector is rotationally fixed to the housing through a splined connection, the engagement and meshing of the floating spline with the splines on the inner surface of the dose selector prevents rotation of the floating spine relative to the body during dose setting and dose delivery. The snap element is also configured with a flexible arm that has a radial extending protrusion that preferably projects outwardly in to engage a plurality of dose stops that are located on an inner surface of the dose selector. These dose stops are designed and manufactured, preferably through a molding process, to be spaced radially apart from each other such that they define a set of finite predetermined fixed doses. During the setting of one of the predetermined doses, the snap element is rotated relative to the dose selector to cause the protrusion on the snap element to engage with and travel over one of the dose stops. Once the protrusion travels over the dose stop and rotation is stopped, this position of the snap element defines a single fixed dose of medicament for delivery. The set of finite predetermined fixed doses includes a lowest fixed dose and one or more higher fixed doses.

[0032]The above described advantage is directly related to the inherent flexibility of the design of the dose selector to achieve any possible number of predetermined fixed dose settings between a zero dose and a maximum dose, including fractional doses of the lowest set dose. This becomes important for a pharmaceutical company that wants to evaluate a new medicament or to evaluate how an existing medicament will impact a different disease state. Especially beneficial is the ability to easily and efficiently design different dose selectors each having a different finite set of predetermined doses, including having fractional fixed predetermined doses instead of having each fixed dose being a multiple of a lowest fixed dose.

Problems solved by technology

This is not possible with dose setting mechanisms currently known.

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